I get a daily email with COVID updates, here are two from this mornings. Sadly, the hyperlinks, to specific articles, are not active. I think that you can subscribe here:
https://www.newamerica.org/internationa ... ily-brief/
(Yes, New America is a left leaning shop, but for the most part these are science based)
Individuals With Type A Blood May Be at Higher Risk for Severe COVID-19; Those With Type O at Lower Risk
A new study published in the New England Journal of Medicine confirmed that blood type may increase a person’s susceptibility to severe COVID-19. Researchers who looked at the “genes of thousands of patients in Europe found that those who had Type A blood were more likely to have severe disease while those with Type O were less likely” (CBS News). The study looked at 1,980 individuals from seven hospitals in Italy and Spain, in addition to “835 patients and 1255 control participants from Italy and 775 patients and 950 control participants from Spain were included in the final analysis” (New England Journal of Medicine). Variations in six genes were found to impact the chances of someone progressing to severe COVID-19, as well as specific blood types. Center for International Blood and Marrow Transplant Research chief Mary Horowitz said that of the four blood groups–A, B, AB, O–people with O are more likely to “recognize certain proteins as foreign, and that may extend to proteins on virus surfaces,” reports CBS News.
In an earlier brief, we noted that geneticists have been looking at human DNA to see if there are genetic predispositions to SARS-CoV-2 infection, and a new preprint manuscript out of Europe indicates there’s a “strong statistical link between genetic variations and Covid-19.” Researchers found two indicators that could increase infection, one of which is blood type. “Type A blood was linked to a 50 percent increase in the likelihood that a patient would need to get oxygen or to go on a ventilator” (NYT). 23andMe Inc. identified a “difference in a gene that influences a person’s blood type [that] can affect a person’s susceptibility to Covid-19,” reports Bloomberg. Results from 23andMe’s 750,000 participants found that “type O blood is especially protective against SARS-CoV-2.” Included in the 750,000 were 10,000 participants who identified that they tested positive for COVID-19. Type O blood makes an individual nine to 18 percent “less likely than individuals with other blood types to have tested positive for the virus.” There was little variance between other non-O blood types and an individual’s susceptibility to the coronavirus and subsequent disease.
Antibodies to Coronavirus May Start to Decline 2-3 Months After Infection, but Immunity May Continue Longer, Suggest Two New Studies in Nature
As scientists continue to investigate the body’s immune response to the coronavirus, in the search to determine the hallmarks of COVID-19 immunity and how long it might last, two new studies provide additional pieces of the puzzle, while highlighting the need for further research. Antibodies to the coronavirus start to decrease within two to three months after infection, scientists in China found after studying 74 COVID-19 patients, half of whom were symptomatic and half asymptomatic (Nature Medicine). However, even low levels of certain antibodies may be enough to neutralize the virus. In a separate study on 149 recovered COVID-19 patients, researchers found that their plasma had “rare but recurring” antibodies “with potent antiviral activity” that bound to the coronavirus’s spike protein, “suggesting that a vaccine designed to elicit such antibodies could be broadly effective” (Nature). Moreover, antibodies are not the whole story of immunity. The immune response includes T cells, which can destroy the virus by killing virus-infected cells, and, in people who have been infected, memory B cells can rapidly produce antibodies again if the body re-encounters the same virus (NYT).
As we’ve noted in previous briefs, infectious disease experts have theorized what immunity from the coronavirus might look like, and how long it will last, but they “still don’t know what potpourri of antibodies, cells, and other markers in a person’s blood will signify that protection,” writes STAT. Both of these studies point to a picture where antibodies to the coronavirus may not last as long in the body as antibodies to the other coronaviruses that cause severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS), which can last for a year or longer. “These reports highlight the need to develop strong vaccines, because immunity that develops naturally during infection is suboptimal and short-lived in most people,” said Akiko Iwasaki, a viral immunologist at Yale University, commenting on the two studies to the New York Times, adding “We cannot rely on natural infection to achieve herd immunity.”
